Lifting columns, which are sometimes referred to as telescopic columns or telescopic actuators, are used in a wide variety of technical fields. They have medical applications, for example, in examination tables and wheelchairs, and in other devices where lifting movement may occur. They are also used outside the medical field, for example, to facilitate the movement of machine parts or other components along a direction of movement.
Lifting columns thus generally comprise at least two tubular or columnar components that are insertable one-into-another along a direction of movement and are thus movable telescopically with respect to each other. Guide elements are often provided to guide the components in order to improve mechanical stability. The guide elements effect a linear supporting of the two components with respect to each other.
The lifting columns are sometimes subject to eccentric loads in addition to the linear shear forces for which they are designed. These loads may occur when the geometric relationship of the components deforms, as a result of frictional forces, for example, but also for other reasons. Some lifting columns are very sensitive to such torques, and these torques may adversely affect the operation of the lifting column. This behavior is particularly noticeable in structurally simple guide elements.
DE 196 23 580 C2 and its US family member U.S. Pat. No. 5,791,233 describe a lifting column which can be used for medical applications, such as in examination tables, or for industrial applications. The lifting columns described in these patents use guide elements which make possible a guiding of corresponding tubular profiles of the lifting columns. These guide elements are multipart, and the individual parts of the guide elements are comprised of different materials.
There is therefore a need to provide a structurally simple arrangement of telescopic lifting column components with guide elements that have an improved ability to withstands torques caused by eccentric loads on the components.